How to Distinguish the Scope of Superglobals in PHP

The superglobals in PHP are:

• $GLOBALS
• $_SERVER
• $_GET
• $_POST
• $_FILES
• $_COOKIE
• $_SESSION
• $_REQUEST
• $_ENV

Don't be confused by the name of superglobals, their scopes vary from one to another:

• $GLOBALS
The scope can be across scripts including functions and methods, but it must be within the same web page.
• $_SERVER
The scope is the same as $GLOBALS.
• $_GET
The scope is the same as $GLOBALS.
• $_POST
The scope is the same as $GLOBALS.
• $_FILES
The scope is the same as $_POST.
• $_COOKIE
The scope can be across pages, sessions, instances until expired, but it must be within the same browser.
• $_SESSION
The scope can be across pages, but it must be within the same session.
• $_ENV
The scope can be across pages, sessions, and instances, but it must be within the same shell.